Sialyltransferase(s) will be extracted from human liver and characterized with regard to their solubility, stability, number of isoelectric forms, substrate requirements and kinetic properties. Attempts will be made to purify solubilized asialofetuin-sialyltransferase by affinity chromatographic methods or conventional procedures (ion exchange chromatography, salt fractionation, gel filtration, etc.). The purified enzyme will be characterized and compared in its properties to the crude sialyltransferase. Studies will be done to characterize sialyltransferases in pathological human livers to determine if altered sialyltransferases are involved in the etiology of (or at least correlated with) malignant transformation or cystic fibrosis. Studies will be carried out to extend our previous finding of altered alpha-L-fucosidase isoenzyme patterns in cystic fibrosis livers by isoelectric focusing of more alpha-L-fucosidase preparations and other sialic acid-containing lysosomal hydrolases as well as by purifying and characterizing the altered alpha-L-fucosidase from a cystic fibrosis liver. Developmental studies will be done to determine the specific activity and presence of various forms of sialyltransferase in fetal livers of various gestational ages. The chemical and functional relationship of the multiple molecular forms of the sialoglycoprotein alpha-L-fucosidase from human liver will be investigated using neuraminidase, sialyltransferase and various kinetic and immunochemical parameters.